If the center is solid by itself, how can external objects move?

——Cheng Hao (written when he was ten years old)

Er Cheng, the brothers Cheng Hao (Ming Dao) and Cheng Yi (Yichuan), were the founders of Neo-Confucianism in the Song and Ming Dynasties. It was Cheng Hao who gave new connotation to "natural principles" and made it the highest category of Chinese philosophy. Some scholars believe that Cheng Hao was the pioneer of Neo-Confucianism in the Song and Ming Dynasties (Baisha, Ganquan, and Yangming all respected Cheng Hao), and Cheng Yi was the pioneer of Cheng-Zhu Neo-Confucianism. In many classics, there is no distinction between Dacheng and Xiaocheng, and they are all called "Chengzi". Generally speaking, those who speak close to the heart are Dacheng, and those who speak close to Cheng and Zhu's Neo-Confucianism are small Cheng. Readers can taste it for themselves. The following famous quotes are taken from "Er Cheng Ji".

There is only one principle in the world.

Everything is just a natural principle.

Heavenly reason says, this truth is even more limited. Not to survive for Yao, not to forget for Jie. If a person obtains it, he will not gain anything if he does great things, nor will he suffer any loss if he lives in poverty.

All things are provided for me, not just people, but all things. All go out from here. It's just that things can't be pushed away, but people can retreat. Although we can push it, when will we get a point? If you can't push it, when will you lose one point? Everything is there, laid out flat. When did Yao Yao fulfill his duties as king and add more to his rule? After Shun's practice, how much more filial piety can be gained? Yuan Lai remains the same.

Note: Heavenly principles are eternal, and moral principles and natural principles can ultimately be attributed to one heavenly principle. The principles of heaven are not only provided by humans but also by things. However, humans can understand and practice the principles of heaven, but things cannot. Regardless of whether people practice the laws of heaven or not, the laws of heaven will not decrease or increase.

Heaven is the principle. God is the speaker of wonderful things. The emperor is famous for being in charge of things.

To say that Huang Tian was angry was not because someone above him was angry, but that was the reason.

Note: God, emperor, emperor and heaven all refer to different aspects of logic.

Everything has its own reason. If you follow it, it will be easy, but if you go against it, it will be difficult.

The way of heaven and earth, the principle of all things, is only perfect. Your Majesty, it is only natural that nature and nurture do not violate the rules.

Note: People should understand and comply with principles. "One yin and one yang is called Tao." Tao is not yin and yang, so one yin and one yang are Tao.

There is no Tao without Yin and Yang, so Yin and Yang are Tao. Yin and Yang, Qi. Qi is a metaphysical thing, while Tao is a metaphysical thing.

Metaphysically, it is Tao, and physically, below it, it is a tool. This must be said. The tool is also the Tao, and the Tao is also the tool, but the Tao is there, and it is not related to the present and the future, oneself and others.

Note: Yin and Yang refer to the interactive cyclic movement of Qi, which is still metaphysical. Tao is the cause of yin and yang, not yin and yang. However, Tao cannot be manifested directly, but must be expressed through yin and yang. Tao is more fundamental than utensils and is a metaphysical existence. However, if there are utensils, there must be Tao. Things are manifestations of Tao, and Tao transcends time (now and in the future) and space, and any individual (self and others). It can also be seen from the relationship between "Tao tools" and "Tao Qi" mentioned by Ercheng that Confucianism is not separated from and values ??the material world and human society, which is obviously different from Buddhism and Taoism.

The smallest one is the principle; the most profound one is the image. The body uses one source, microscopically seamless.

The most obvious thing is nothing like things, and the most trivial things are nothing like reason. But things and principles are consistent, and the subtle manifestations have the same source.

Notes: Xiang refers to all phenomena; Shi refers to all things, which are superficial and obvious. Reason is the root or essence of images and things, which is latent and intrinsic; reason, images and things are unified, and their combination is "infinite".

The principles of heaven and earth and all things are not unique and must be right. They are all natural and not arranged.

There is a right in all things, one yin and one yang, one good and one evil.

There is yin and yang between heaven and earth, and there is good and evil.

Note: The unity of opposites is the law of all things, and the principle of ontology is perfection.

In heaven it is fate, in righteousness it is principle, in man it is nature, and it governs the body and mind. Actually one.

One person’s heart is the heart of heaven and earth, and the principle of one thing is the principle of all things.

Human relations are the principles of nature.

The mind alone is heaven, and when it is exhausted, it will be understood, and when it is understood, it will know heaven. It should be convenient for everyone, let alone ask for it from outside.

The mind is the same, some refer to the physical body, and some refer to the use. Just watch what you see.

Note: Confucianism is consistent. Whether it is fate, nature or reason, it is ultimately implemented through the heart. Confucianism still pays more attention to the principles of morality, and the same goes for Ercheng. Therefore, it is natural to say that "you cannot seek it from outside." This certainly does not mean that you should not study the principles of things. Er Cheng is very interested in "physics" and believes that "physics is the most fun". He has done research or reasoning on issues such as geography and wind and rain, water, soil and plant growth, and drilling wood to make fire.

The so-called concentration means concentration when moving, and concentration when stillness. There is no approaching, no inside or outside. Gou regards foreign things as external and leads oneself to follow them. This is why nature is regarded as having both inside and outside.

A sincere person combines the internal and external principles; if you are not sincere, there is nothing.

A scholar’s ??first priority is to fix his or her ambition.

Scholars need to respect this mind and not be impatient. They should cultivate it deeply and swim in it, and then they can be content with it.

Learning requires respect and sincerity, and there is a "benevolence" in the middle.

All knowledge, hearing it and knowing it, is not acquired. Those who have gained it must have a clear mind.

Note: Movement and stillness, inside and outside, are "one". If movement and stillness or inside and outside are regarded as "two", it cannot be said to be "concentrated" and the nature will be separated. "Sincerity and respect" is the self-cultivation skill advocated by Ercheng. Through sincerity and respect, benevolence can be gained. The main body of Kungfu and learning is the heart.

Conscience and ability have no origin. They come from heaven and are not tied to humans.

The human heart is full of knowledge, but if it is obscured by human desires, it will destroy the virtue of heaven.

If you know it, you will be sincere. If there is anyone who knows it but is not sincere, you will know that you have not arrived yet.

Annotation: Er Cheng also talked about conscience and knowledge. He affirmed the innate nature of conscience and believed that the pursuit of knowledge is also a work of sincerity and respect. He pointed out that human desires can blind conscience.